If you just Google "grants" a lot comes up.
It's easiest to be specific -- like "grants disaster relief," whatever applies best.
But for example this was the first result when I Googled "grants":
When I plugged "Haiti" in that, I got this one (among others):
If that link doesn't work, a copy and paste:
Centers for Disease Control and Prevention
The purpose of this FOA is to provide technical assistance and support to Haiti’s Ministry of Health (Ministère de la Santé Publique et de la Population MSPP) in its post-earthquake and post-cholera response for the implementation of surveillance surveys and evaluation projects for public health decision making. This FOA will also allow technical assistance and research activities and evaluations to respond to other diseases that may occur during the project period.
Non-profits are eligible (but not just non-profits, lots of others too).
Grant amounts range from $100,000 (bottom) to $1,000,000 (top).